Nivelles (nivɛl; Nijvel, ˈnɛi̯vəl; Nivele; Neyvel) is a city and municipality of Wallonia located in the Belgian province of Walloon Brabant. The Nivelles municipality includes the former municipalities of Baulers, Bornival, Thines, and Monstreux. The Nivelles arrondissement includes all the municipalities in Walloon Brabant. The Collegiate Church of St. Gertrude has been classified as a heritage site of Wallonia. Starting in 4,000 BC, the Nivelles region was gradually turned into agricultural land by the Danubian settlers. Most of their ancestral Rubanean civilization was destroyed by the Roman invaders during the first century AD. In turn, most of the Roman constructions, including villas, were destroyed during the Germanic invasions of the 3rd century. In the 7th century, the territory was part of the Austrasian Frankish kingdom, and the Mayor of the Palace, Pippin of Landen, rebuilt a villa there that covered more than 78 km2. After Pippin's death in 640, the bishop of Maastricht, the future Saint Amand, urged Pippin's widow, Itta, to found an abbey in their villa. Itta's daughter, Gertrude, became the monastery's first abbess and was venerated as a saint upon her death. The growing influx of pilgrims necessitated the construction of ever-bigger churches, which culminated in the huge Romanesque structure that still stands today. The dedication of the church took place in 1046 in the presence of Wazo, Prince-Bishop of Liège, and Henry III, Holy Roman Emperor. This was the golden age of the Nivelles monastery, which now owned territories as far as Friesland, the Moselle and the Rhine. In the 13th century, the city that grew around the church became part of the Duchy of Brabant. The population was mainly artisans and guild members, who did not hesitate to fight the abbesses and the dukes to obtain their rights. These rights were finally granted by Joanna, Duchess of Brabant in the 14th century. In 1647, an important uprising by the thread manufacturers resulted in many of the city's entrepreneurs leaving for France, leading to the city's economic decline.